


Blue Velvet

by hauntedspaceman



Category: Shall We Date?: Obey Me!
Genre: Anal Sex, Bathtub Sex, Blow Jobs, Double Penetration in One Hole, Hair-pulling, Hand Jobs, Incest, Kissing in da gamer chair, Leviathan Has Two Penises (Shall We Date?: Obey Me!), Lucifer has like...a line, M/M, Mammon crushes hard for a bit, Porn with Feelings, Sibling Incest, Spit As Lube, bc bathtub is his bed haaaa, bottom!levi, top!mammon, two Dicks
Language: English
Status: Completed
Published: 2021-02-19
Updated: 2021-02-19
Packaged: 2021-03-14 19:06:56
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,876
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29546982
Author URL: https://archiveofourown.org/users/hauntedspaceman/pseuds/hauntedspaceman
Summary: A change in hair apparently changes how Mammon views his weeb brother.
Relationships: Leviathan/Mammon (Shall We Date?: Obey Me!)
Kudos: 63





	Blue Velvet

**Author's Note:**

> Song name title bc no thoughts head empty

Mammon was relieved to be back home, even though he wouldn't admit it. He enjoyed his vacation with Yuki in the human realm but.. Being so far from his brothers for so long was just usual. Still, he was glad she picked him to go, in her own words it was because they were best friends. The second born hoped his siblings were as excited to see him as Yuki was excited to leave with him. Surely his little brothers missed the great Mammon enough to throw a welcome home party!

Nobody was at the door to greet him. He couldn't give up hope yet! If they weren't at the door, maybe they were in the living room setting up. Like a surprise party! He started to pick up his pace as he made his way to the living room, excited by the idea, with a grin plastered on his face. "The great Mammon is h-"he paused, looking at his brothers just doing what they would be on a normal day. Hell, Levi wasn't even in the room with everyone else. He sighed softly. It stung. The avatar of greed didn't know what he expected or why he expected anything, honestly.  
The prideful first born glanced up from his book, giving a little bit of a smile. "Ah, Mammon, I see you're finally back, "he stated. Well, Mammon would take what he could get for a warm welcome.  
"Ahh, hey, Lucifer! Hope you didn't get too bored while I was gone!"he exclaimed, quick to mask his disappointment with his usual somewhat hyper attitude. The conversation didn't go much farther than basic small talk or just asking if the trip was fun. Fun. The second born felt like a fool for expecting large amounts of fanfair to celebrate his return.  
At least spicy ramen wouldn't let him down. 

With a frustrated sigh the white haired demon slunk into the kitchen. The kitchen wasn't empty when he entered, someone rummaging through the fridge. Great. Now he'd have to wait a bit for his food. It hopefully wouldn't be too long, the greed demon just wanted his ramen and to head back to his room. The rummaging lasted only a bit longer, thankfully, but it took Mammon a moment to recognize the demon who moved away from the fridge after shutting the door. It was a strange and foreign sight, to be honest. The other demon's blue-ish purple hair had grown to where it just about hit his collarbone, going slightly past his shoulders ,as his attempt at using his headphones like a headband was failing. Stray hairs fell down, getting in the way of his face but not like how his bangs used to, only one eye was even covered by his bangs. The third born raised an eyebrow as he made eye contact with Mammon, who was… obviously staring. "Eh, you're back already?"Leviathan paused for a moment when Mammon didn't answer immediately. "...Why are you looking at me like that? Forget what a yucky otaku looks like..?"this question came out much more irritated sounding. 

Yucky definitely wasn't a word he'd use to describe Levi on a normal basis. He definitely wouldn't use it right now. The second born shifted slightly on his feet before replying. "N-no, no, no! I just didn't expect to see you here!"Mammon replied, giving an awkward little chuckle. It was weird, Levi's eyes not being ninety percent covered by his long bangs. The greed demon had never really...noticed his younger brother's eyes before. Surely it just caught him off guard..right?

The third born's gaze was slightly suspicious, but,he soon turned his attention back to the snack he got from the fridge and began his trip back to the living room. Mammon stood there for a moment, the gears in his head turning as those slight butterflies in this stomach continued to flutter. Blinking a few times before he moved over to the pantry, he was still confused by..those feelings. Lucifer was occasionally correct about Mammon not exactly being the brightest crayon in the box, but he knew what that feeling was. Usually he was a bit more oblivious to little things like that. Maybe it was because it was Levi, of all demons? The greed demon had to brush it off temporarily, getting out his cup noodles. He put his focus more on making his noodles and heading to his room.  
\--  
Mammon got more frustrated as his first couple of weeks home went on. It felt like every time he and Leviathan interacted. He'd trip up, stumble over his words, getting only more angry with himself whenever his younger brother caused his heart to flutter. It felt like his brain picked up on everything the younger did and every time it changed. He'd begun to notice how Leviathan pursed his lips slightly as he concentrated on his games and how the pins on his jacket were just ever so slightly out of line. He was both surprised and thankful none of the others seemed to notice it, he really didn't want anymore reasons for them to trade and berate him.  
It felt ridiculous, something like a simple change in hairstyle making him feel such a way for his dweeb of a brother. Mammon wasn't that shallow though, just falling for for someone because of looks. It wasn't like this was some magical makeover scene in a crummy chick flick and a simple change would make him fall instantly. The more the thoughts ran around in his head, the less sense it felt they made. Of course, Levi had always had things about him that made Mammon drawn to him, in a sense. He was easy to irritate and even easier to get flustered. It was… cute. And despite anime being lame, Mammon would listen to him ramble on about it sometimes. It was nice, seeing how much the other demon enjoyed something. Despite how often they ended up at each other's throats over money or some figure, Mammon did enjoy his company… 

The greed demon groaned as he laid down on the couch in his room, thinking. It'd become a routine by the month's end. Unfortunately so had other things. Like his awkward interactions with Leviathan. He was usually a bit better at handling these things, now he was handling it like… Well, more like how Levi would! The great Mammon knew he wasn't the best romantic out there, but he was better than this! He'd attempted to just talk to the third born about it and failed, repeatedly. He'd stutter and stumble over his words or simply give up and chicken out. It seemed like just telling the other outright was out of the question at this point. So was asking him to a normal date, as he was well aware Leviathan was too much of an introverted shut in to go. Mammon had to think… what exactly could he do?  
The white haired demon put his plan to action within a few hours of coming up with it. He made his way to Levi's bedroom door, letting out a soft sigh as he stood there. Before he could even debate on backing out once again, he knocked on the door. "Password?"the irritated voice of the avatar of envy questioned, post sigh. 

"Ya know I don't know your dumb password…"Mammon huffed, " 'Wanted to ask if you.. Wanted to watch that seven lords thing you like so much. With me.". The response took a moment. 

"...I'm not giving you any money-"

"I don't want any money!"he quickly retorted. "Am I really not allowed to just hang out with you because I want to?". Leviathan opened the door after another moment of silence, gesturing for the other demon to come into his room. 

"Fine, fine. Only because you want to watch TSL,"the third born mumbled. Mammon entered the room, a bit of a grin on his face. The greed demon plopped down in the other's gaming chair, spinning himself in a small circle when he did. Levi still looked irritated, probably a bit more than before considering Mammon was just spinning in his chair.  
Mammon watched as his brother rummaged through his various shelves of DVDs and merchandise for a bit, holding a decent stack of cases when he was done. He set them on the computer desk in front of his older brother. Mammon thought about how much he, Beel, and Yuki had watched a decent chunk of the series but this was at least double that. It was… an intimidating amount of media in a sitting. At least for Mammon. Although he was well aware binge watching a huge series was just the norm for his brother, it was still a lot. The third born nudged the chair over a bit, scooting Mammon out of his way, putting one of the discs into his computer after popping open a case. He smiled a bit as he turned his attention to the older demon. "Ready?"he asked, the pre-feature DVD ads beginning to play on his center monitor.  
\--  
Mammon was a bit frustrated with how his plan was failing so far. He'd been off and on leaning against the gaming chair and the desk for the past hour. He had the intention of just being nice and letting Levi sit, especially because it was the other's room, but in that moment it seemed to have slipped his mind just how long the series was. He nudged the younger demon gently. "Ey, Levi stand up a sec,"he muttered. He received a slight glare before nudging Leviathan again. "C'monnnn, please? My legs are crampin', Levi!". The sea demon groaned in mild frustration as he stood, leaning against his desk after quickly pausing the anime, making sure not to miss any of it. Mammon thought it was a bit odd, considering how many times Levi had sat through this show but he couldn't say anything. Mammon sat down, stretching a bit to get comfortable.

"Now where exactly am I supposed to sit?"Leviathan asked, resting his chin on the back of the chair. The second born demon gave him a little cheeky smile, patting his own lap. "...No,"the third born replied. 

"Levi, it's just my lap! We used to watch stuff like this!"

"Next to each other, not on each other! You're trying to blackmail me later aren't you, you sc-"the avatar of envy was yanked into the greed demon's lap, Mammon letting out a chuckle. Leviathan attempted to wiggle free for a minute or two, his older brother having his arms tight around his waist. He went practically limp for just a minute before beginning to attempt wiggling out of Mammon's grasp once again. "Mammon, let me go! Now!"he whined. He turned around slightly, in a plea to be released.  
Leviathan's face was flushed red hot, a rather pouty and frustrated look on his face. The deep blush even spread to his ears, which Mammon found adorable. 

"Aw, c'mon, little bro~! How can I let you go when you look so… cute… in my arms?"Mammon teased softly. He paused a bit when telling the younger he was cute, as Mammon had always struggled being straight forward when he felt things like this. It was easier if he was drunk, but he was smart enough to know he'd attempt to blame it on the booze the moment he sobered up.  
Leviathan froze and tensed at his words, the blush on his face somehow getting deeper. 

"N-Now you're just making fun of me..! You scumbag!"Levi exclaimed, his voice shaking slightly. "I'm not c-cute!". There was obvious distress in the other demon's tone and Mammon knew he needed to calm him quickly. The last thing he wanted was Levi to lose it and turn to his demon form just because he didn't do this right. Or at least, right for Levi. The older demon pressed one hand flat against Levi's belly, pressing the other closer to him as he pressed his lips to Levi's neck. He nuzzled him gently, ignoring the indigo hair in his face as he gently pressed a kiss to the younger's neck. He could hear his brother's breath hitch gently as he pressed another gentle kiss to his neck. The greed demon gently exhaled, the two sitting in silence for only a few moments as Mammon nuzzled the third born's neck. "Wh-what exactly are you trying to do… ? Blackmail me? M-make fun of me… ? This isn't v-very funny, Mammon," Levi sighed, his voice shakey and sounding mildly exasperated. 

"...I like ya. I like ya.. A lot. You're so… beautiful. Pretty. I-"Mammon hesitated to continue as he awaited his younger brother's reaction. There was nothing yet. "I.. I want you all to myself. I'm not after nothin' but you, Levi,"he sighed, heat beginning to rise in his cheeks. His nerves felt a bit fried after a confession like that, especially with Levi still being silent. He wasn't sure what to do if Levi reacted poorly. What was he supposed to do… ? Before he could think more or add anything else, his brother finally spoke up. 

"Let me.. Let me turn around,"Levi weakly attempted to demand. Mammon pulled his face away, moving his arms as well, allowing him to get up a move. It felt like his face was trying to catch fire as Levi straddled him in the chair, the younger's gaze at his lap. They sat in silence for a minute or two. This was.. A little awkward. It was to be expected and Mammon had fully expected it but, he didn't expect it to be as awkward as it was. In some attempt to ease a little tension, he gently placed his hands on Leviathan's stomach. He moved one hand, placing it under the other's shirt and resting it on his warm tummy. The otaku was quick to cover his face with one of his hands in embarrassment. Levi's body was soft, compared to his own. Back before their fall and even when the younger demon was more active in his duties as the admiral of the navy, he was rather built. A lot had changed since the introduction of things like anime and video games. And Mammon loved it. He smirked a bit to himself as he continued to touch the other, moving his hand up a bit more, getting a shakey breath and a slightly irritated glance from Levi as he gently squeezed his side. 

"How come you're so cute, hm~? It ain't fair… Centuries go by and you just keep getting prettier, not lettin' anybody have ya,"Mammon huffed softly. Using his free hand, he gripped Levi's hip gently. "Let me have ya...At least just this once...". The greed demon chewed his lip as he watched Levi, looking the younger up and down. 

"...Sh-shut up… Just kiss me already or something.."Levi whispered, his voice shaking more than before. Once given the go ahead, Mammon quickly initiated a loving kiss. Without intending to, it began to grow.. Sloppy. Sloppy and hungry. It definitely wasn't the initial goal, for them to be aggressively kissing how they were the first time. His greed really got away from him in the moment, didn't it?  
Mammon imagined what it It felt like he'd been waiting forever to kiss Levi, hungrily nipping at the other's bottom lip. Levi let out soft whimpers as his older brother practically abused his bottom lip, biting and pulling on with his fangs. It only egged Mammon on, digging his nails into Levi's soft hip as he readjusted a bit. Mammon had the goal of putting his tongue into his younger brother's mouth, but shockingly, Levi beat him to it. Mammon nearly gagged as Levi's long, forked tongue attempted to force it's way down his throat. It felt like the damn thing had a mind of its own, tears gently pricking Mammon's eyes as he began to suck on the wet muscle. Though his tears blurred his vision, he managed to look up, noticing the horns that had appeared on the sea demon's head. It was in the same instant, Mammon heard Levi's tail thud against his desk, quickly moving about due to all this sudden stimulation.  
The older demon removed his hand from Levi's shirt, gripping the thick base of Levi's snake like tail, startling the other another to make him pull away, a groan exiting his lips as he did so. The older demon felt his dick twitch in his pants at the guttarl sound, gently nibbling his own bottom lip. Mammon had to at least catch his breath a little before speaking, his younger brother giving him a slightly confused scowl as he waited for Mammon to say something about why they stopped so soon. 

"I-I think we gotta move to your bed... "Mammon panted out, gesturing a bit to Levi's tail and horns. Levi blinked a few times, feeling the top of his head, his embarrassed expression from earlier returning as he gripped one of his horns.  
It was an awkward move to the bed, Mammon practically carrying the envious demon as they stumbled into the bed, still entangled together. Levi was underneath Mammon, the younger demon's face still as flushed when they began. Being the tub like bed was still awkward, even if less so than the gaming chair, as it was a bit of a squeeze for the two of them. Levi's tail wrapped itself around Mammon's upper thigh as the older demon leaned down, beginning to nip and kiss at his neck, almost as hungrily as when the greed demon kissed him before. Mammon growled as he felt Levi's nails dig into his shoulders, biting down on the younger's neck harder than before. After leaving plenty of marks on Levi's neck, he went back to kissing the younger's slightly puffy, abused lips. Mammon enjoyed taking in all of Levi's sounds, all of them muffled against his own lips as they continued to kiss. The older demon could feel a wetness forming in his boxers from his cock beginning to drool, shifting slightly as he attempted to contain himself and go slow for his brother. But as always, his impulses got the best of him. 

He quickly undid his belt before quickly tugging down Levi's sweatpants and boxers, pausing for a moment at the sight before him. He blinked twice, making sure he was actually seeing things correctly. Leviathan had two dicks. Well, it could be better described as a hemi-penis, as they shared a base. And they were both dribbling pre-cum.  
"I-I'm sorry! I know it's not n-normal, but-"the younger demon was interrupted with a moan, the older having begun to stroke lower cock. The untouched cock twitched as Mammon's hand quickly picked up pace, whines and soft sounds escaping the younger's lips. The elder of the two bit his bottom lip, focusing on jerking Leviathan off, relishing in all the noises his younger brother failed to hold back.He was slightly surprised at just how loud the other got, the sounds of pure ecstasy slipping out practically every stroke.  
Mammon pulled his hand away, causing Leviathan to whimper out something about being "so close". The older demon leaned down, struggling for a moment as put both cocks into his mouth. He could barely move up and down the shafts, drool dribbling down Leviathan's dual cocks as Mammon worked with his tongue. The piercing Mammon had on his tongue created such an unexpected pleasure, Levi's back attempting to arch as the sounds escaped him once more. He bucked his hips upward, forcing Mammon to take in more of his cocks as he came. With so much space taken up by the cocks in his mouth, it made quite a mess. Cum dribbled down his chin, a slightly startled look on his face from the sudden filling of his mouth. 

The older demon pulled his mouth on the two dicks, licking his lips and wiping at his face before saying anything. Levi panted, now hiding his face in embarrassment. "M-My turn... "Mammon muttered out, his face brightly flushed as his breathing was a bit labored. 

"E-eh..?"

"My turn n-now...Turn around for your big brother, will ya?"he questioned, it not even really being that demanding of a tone. The younger demon did his best to lay on his stomach, the whole process of turning around in a tub was awkward and a tad uncomfortable, especially with how his cocks were pressed against his stomach. Mammon only had to tug down the other's pants a bit more before he quickly began undoing his belt and jeans, yanking down his own boxers for his leaking erection to pop out of them. Without a thought the older demon spit in his own hand, giving his cock a few strokes before he positioned himself a bit better. Placing his hands on Levi's ass to gently spread his cheeks before he slowly began to push into him. The sea demon below him moaned, whining as more of Mammon's cock was pushed into his entrance. The greed demon was still for a bit, gently petting the younger demon's back, whispering soft words of encouragement to him. 

"Y-You can move now… "Levi whimpered out softly, glancing back at his older brother. Mammon promptly began to thrust, his speed quickly going from slow and steady to quick and shallow. The free demon felt the wings and horns appear as he continued, feeling a bit embarrassed by the twitching of his somehow overstimulated wings. His eyes were shut tight, feeling his wings begin to flap wildly each time he thrust into his little brother. Heat pooled quickly in his stomach, feeling it tighten as he continued to thrust in and out. The older demon moved a hand off the younger demon's soft hips, moving up to tug Levi's hair. He'd thought about this often, pulling on the other demon's hair just to make him squirm and writhe beneath him. And Levi reacted just as expected, writhing under Mammon and moaning.  
Mammon bit his bottom lip harshly, muffled moans attempting to escape his lips as he picked up pace more, his movements becoming sloppy and shallow the closer he got to finishing. "Mm.. M-Mammon..! I.. a-ah..coming again..! "he whined out. Leviathan tightened around him, the younger demon coming once again, whimpering as the older thrust in his a few more times. Mammon let out a guttural moan as he came inside Leviathan. He slowly pulled out, some cum leaking out of Levi's hole. The younger demon moved, turning back onto his back, pulling the other demon onto him, cuddling him tightly. 

"...You got your mess on me,"Mammon huffed after a moment. 

"We already need showers,"the envious demon mumbled, nuzzling into his older brother. The now tired greed demon was practically purring, content with snuggling closer to Leviathan. He placed a gentle kiss on his brother's lips before returning his head back to where it rested before. 

The two demons quickly fell asleep, without a thought as to how they'd explain everything at breakfast the next morning.


End file.
